[css-houdini-drafts] [css-properties-values-api] Clarify parsing of duplicate descriptor declarations (#1112)

cdoublev has just created a new issue for https://github.com/w3c/css-houdini-drafts:

== [css-properties-values-api] Clarify parsing of duplicate descriptor declarations ==
I am sorry because the following situation is rather unlikely...

```css
@property --custom {
  inherits: false;
  syntax: '<length>';
  syntax: '<unsupported>';
  initial-value: 1;
  initial-value: 1px;
}
```

... but is it an invalid custom `@property` registration?

  > The `initial-value` descriptor’s value must parse successfully according to the grammar specified by the syntax definition. [...] If the above conditions are not met, the `@property` rule is invalid.

I suggest to add the something similar to this in the introduction of [3. The `@property` Rule](https://drafts.css-houdini.org/css-properties-values-api-1/#at-property-rule):

  > Descriptor declarations in `@property` are parsed like property declaclarations in a style rule: if a descriptor is declared multiple time with a valid value, only the last declaration remains.

Please view or discuss this issue at https://github.com/w3c/css-houdini-drafts/issues/1112 using your GitHub account


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Received on Wednesday, 18 October 2023 14:05:42 UTC